Automated Transition from 3D to Integrated Vehicle Model in System Simulation

Abstract

The pace of change that the automotive industry is experiencing in the recent years is unprecedented. For legislative and market driven reasons, the automobile is moving away from the internal combustion as the sole means of propulsion towards more innovative system architectures. Almost every new vehicle is electrified to a certain degree, ranging from mild hybrids to battery and fuel-cell electric vehicles, which significantly increases the number of components and systems that need to be integrated and balanced to ensure the maximum efficiency of the powertrain. Combining this with the increased amount of vehicle variants present on the market, it becomes clear that engineers must consider many scenarios. Powertrain components, such as e.g. the battery, e-machine, power electronics can operate safely and efficiently only in a very narrow temperature band. Therefore, thermal management is critical. The heat transfer phenomenon in nearly every automotive component are quite complex and can only be analyzed effectively by using detailed 3D simulation models (CFD, FEA). However, due to their complexity they are computationally ineffective, especially considering that a lot of investigations that need to be conducted are of a transient nature. Consequently, an equivalent 0D simulation model must be set up. Such a model, provided it is sufficiently accurate, can be used to analyze the transient behavior of individual components and its impact on the entire vehicle system and vice versa. The presented work demonstrates the automated transition from a CFD model to a 0D simulation model. The resulting model is integrated into a vehicle model, where simulations of a legislative drive cycle at various conditions are performed and the impact of various loads on the investigated component are analyzed.